"Hip rotators" refer to the muscles in your hips that allow you to rotate or turn your legs. They help you move your legs sideways or in a circular motion. Full definition
(True sciatic pain occurs when the sciatic nerve is pinched by lumbar vertebrae at the nerve root, or trapped under or inbetween tight deep hip rotator muscles.) (physiologicnyc.com)
Sciatic pain, or sciatica, is most commonly caused by compression or irritation of the sciatic nerve that runs from each side of the lower lumbar and lumbosacral spine through the buttock and all the way down to the foot and in most cases, it's the piriformis muscle (a small hip rotator muscle located in the buttock region) that irritates the nearby sciatic nerve, thereby causing pain and numbness. (fitnessandpower.com)
The piriformis works along with other hip rotators to turn the hips and upper leg outward (external rotation of the hip). (verywellfit.com)